package com.hmdp.service.impl;

import com.hmdp.dto.Result;
import com.hmdp.entity.SeckillVoucher;
import com.hmdp.entity.VoucherOrder;
import com.hmdp.mapper.VoucherOrderMapper;
import com.hmdp.service.ISeckillVoucherService;
import com.hmdp.service.IVoucherOrderService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.utils.RedisIdWorker;
import com.hmdp.utils.UserHolder;
import org.springframework.aop.framework.AopContext;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import javax.annotation.Resource;
import java.time.LocalDateTime;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class VoucherOrderServiceImpl extends ServiceImpl<VoucherOrderMapper, VoucherOrder> implements IVoucherOrderService {

    @Resource
    private ISeckillVoucherService seckillVoucherService;
    @Resource
    private RedisIdWorker redisIdWorker;
    @Override
    public Result seckillVoucher(Long voucherId) {
        // 1.查询优惠券
        SeckillVoucher voucher = seckillVoucherService.getById(voucherId);
        // 2.判断秒杀是否开始
        if (voucher.getBeginTime().isAfter(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀尚未开始！");
        }
        // 3.判断秒杀是否已经结束
        if (voucher.getEndTime().isBefore(LocalDateTime.now())) {
            // 尚未开始
            return Result.fail("秒杀已经结束！");
        }
        // 4.判断库存是否充足
        if (voucher.getStock() < 1) {
            // 库存不足
            return Result.fail("库存不足！");
        }

        Long userId = UserHolder.getUser().getId();
        synchronized (userId.toString().intern()) { //这里是防止用户重复领卷(但是每次都会new一个新对象,所以用to string,但是新字符串也是一个新对象所以用intern())
            //获取代理对象(事务)
            IVoucherOrderService proxy = (IVoucherOrderService) AopContext.currentProxy();
            return proxy.createVoucherOrder(voucherId);
        }
    }

    @Transactional
    public Result createVoucherOrder(Long voucherId) {
        // 5.一人一单逻辑
        // 5.1.用户id
        Long userId = UserHolder.getUser().getId();

            long count = query().eq("user_id", userId).eq("voucher_id", voucherId).count();
            // 5.2.判断是否存在
            if (count > 0) {
                // 用户已经购买过了
                return Result.fail("用户已经购买过一次！");
            }
            //6，扣减库存
            boolean success = seckillVoucherService.update()
                    .setSql("stock= stock -1")
                    .eq("voucher_id", voucherId).gt("stock", 0)
                    .update();
            if (!success) {
                //扣减库存
                return Result.fail("库存不足！");
            }

            //7.创建订单
            VoucherOrder voucherOrder = new VoucherOrder();
            // 6.1.订单id
            long orderId = redisIdWorker.nextId("order");
            voucherOrder.setId(orderId);
            // 6.2.用户id
            // Long userId = UserHolder.getUser().getId();
            voucherOrder.setUserId(userId);
            // 6.3.代金券id
            voucherOrder.setVoucherId(voucherId);
            save(voucherOrder);

            return Result.ok(orderId);
        }

}
